Routing video, data, and voice traffic at high bit rates via Ultra Long Haul (ULH) or metro optical networks is substantially increasing in modern communications systems. Some variants of such systems transmit optical signals through optical fibers via dense wavelength division multiplexing (DWDM), in which multiple wavelengths of light are transmitted simultaneously through a single fiber. DWDM systems typically employ devices called reconfigurable optical add/drop multiplexers (ROADMs) to add and remove signals from the network in a purely optical manner, without requiring conversion to/from the electrical domain.
In a typical metro optical network architecture, traffic protection against various network failures is provided by doubling the network capacity over the projected traffic (also referred to as 1+1 protection architecture). Thus, the typical architecture offers an inefficient use of resources and limits network growth.